Lubrication



PM... Feb. .1, 1944 LUBRICATION Amos T. Knutson and Eldon F. Graves, Midland,

Mich, assignors to The Lubrl-Zol Corporation, Cleveland, Ohio, a corporation of Ohio No Drawing. Application April 2, 1935, Serial No. 14,295

4 Claims. (01. 252-53) This invention relates as indicated to lubrication and more particularly tothe provision of a lubricating composition capable of withstanding greater pressures per unit area before seizure and scoring of the bearing surfaces takes place than such pressures as a pure mineral oil may, for example, withstand.

It is a more particular object of this invention to provide a lubricating composition which is of such nature that it will react with the bearing surfaces in such manner as to be particularly effective for use under conditions resulting-in thin film lubrication which maintain when the pressure between the bearing surfaces is in the neighborhood of or in excess of approximately 10,000 pounds per square inch.

It is a further object of this invention to provide a lubricating composition and a method of improving the lubricating properties of a lubri-,

eating oil such as pure mineral oil particularly to increase the break-down pressure of the film of such oil between bearing surfaces, and consequently to improve the thin film lubricating characteristics of the oil.

Other objects of the invention will'appear as the description proceeds.

Our invention, then, consists of the steps hereinaftel' fully described and particularly pointed out in the claims, the following description setting forth in detail certain steps embodying the invention, such disclosed steps constituting, however, but one of the various ways in which the principle of the invention may be used.

The present invention contemplates the provision of a lubricating composition which contains organic derivatives of inorganic oxy-acids, such compounds being used with or without being admixed with a suitable 011 base such as a mineral oil.

Where the lubricating composition in accordbase and the addition agent.

ance with the present invention comprises such admixture, the components thereof may, as previously indicated, be broadly classified as the oil The oil base The suitable oil base comprising one of the components of the lubricating composition of the present invention may be any suitable lubricating oil such as a mineral or vegetable oil or any suitable oil usable forpurposes of lubrication. Furthermore, this invention contemplates the use as lubricating oil base of oils generally which may have been subjected to a particular treatment for the purpose of imparting thereto characteristics not originally possessed thereby and which render the same particularly suitable or in any event do not render them harmful for use as lubricants.

Addition agents The so-called addition agents, as previously explained, which are contemplated for use in lubricating compositions made in accordance with the present invention, may be broadly classified as organic derivatives of inorganic oxy-acids. Inasmuch as lubricating oils may on occasion be subjected to elevated temperatures the more stable of such compounds are preferred. It will be found that such compounds of the class enumerated as having a boiling point'of over C. or

at most C. will be best suited for the purpose in contemplation for the reason that they It is believed that the above identified broad class of compounds contemplated for use by this invention and generically defined as organic derivatives of inorganic oxy-acids may be conven iently classified in the following manner, viz:

I. Classification according to nature of acid from which compound is derived. Compounds may be derivatives of:

1. Sulphuric acid 2. Phosphoric acid 3. Carbonic acid 4. Sulphurous acid 5. Phosphorous acid 6. Nitric acid 7. Nitrous acid 8. Oxyhalogen acids, c. g.:

(a) Hypochlorous (b) Chlorous (c) Chloric (d) Perchloric 9. Cyanic acid v The esters may be further classified as follows:

(1) According to whether or not all replaceable hydrogen of inorganic acid has been replaced by organic radicles:

(a) Acid esters, containing one or. more replaceable hydrogen atoms of original acid, e. g. phenyl phosphoric acid.

(b) Neutral esters, containing no replaceable hydrogen atoms of original acid, e. g. (di)ethyl sulphate; triphenyl phosphate.

(2) According to nature of organic radicles.

(a') Alkyl esters. (b') Aryl esters. (0') Mixed alkyl-aryl esters.

III. Classification of the halogen bearing compounds, according to nature of attachment of halogen atom.

(A) Halogen atom attached to carbon atom which is part of an open chain structure.

(3') Halogen. atom attached to carbon atom which is part of a ring structure.

(1") Where ring structure is of henzenoid type (including hetero geneous ring structure of benzenoid type).

(2") Where ring structure is of cycloalkyl type (i. e. of type including cyclo-paraifins, cycle-olefines and cyclo-acetylenes).

\ (3") Where ring structure is of heterogeneous type but other than benzenoid, e. g. derivatives of the hydro-jurans.

This invention also contemplates the use as addition agents of metallic salts of any of the organicacid compounds referred to, e. g. sodium salts of the benzene sulphonic acids. These are designated by an asterisk in the following table.

Specific compounds which are examples of the foregoing classes of compounds and which are all organic derivatives of inorganic oxy-acids are as follows: (The indicia at the right of the names of the compounds denote their places in the foregoing tables).

Classification II III Derivatives of sulphuric acid Esters-sulphates Acid estershydrogen sulphates- Ethyl hydrogen sulphate Benz lhydrogen sulphate. Neutra esters.

Sulphonic acids and sulphonetea- Benzene sulphonic acid p'Phenyl benzene sulphonic aci l-emino S-naphthol sulphonic acid 2-na hthol 3-6 disulphonic acid.

Nap thalene 1-5 disuiphonic acid Toluene sulphonic acid enzene sodium sulphonate.

Sodium salt of p-phenyl sulphonic acid Sodium p-naphthol disulphonate (2-6-8) Ethyl benzene sulphonate Halogen-bearing compounds:

Di Ep-chlorethyl) sulphate Di o-chlorbenzyl) sulphate Classification I H III Derivatives of phosphoric acid 2 Esters-phosphates 2 A Acid esters-alkyl and aryl phosphoric acids 2 A (a;

Mono-ethyl phosphoric acid 2 A (a (a) Mono-lnuryl phosphoric acid. 2 A (a) a) Di-ethyl phosphoric acid 2 A a) a) Di-Iauryl phosphoric acid-. 2 A (a; (a'; Mono-phenyl phosphoric acid 2 A (a (b Di-phenyl hosphoric acid... 2 A Mono-ethy mono-phenylphosphoric acid 2 A (a) (c) Neutral esters. 2 A (b) Tri-ethyl phosphate.. 2 A (b) (a') Tri-(n-butyl) hos hate 2 A (b) (a) Tri-isobntylp osp ate- 2 A (b) (a') 'I'ri-lauryl phosphate 2 A (h) (a) 'Iri-phenyl phosphate" 2 A (b) (b') 'Iri-(p-cresyl) phosphate 7 2 A (b) (b') Tn-(o-cresyl) phosphate 2 A (b) (b') 'lri-(p-tert.-bntyl phcnyl) phosphate-- 2 A0) (b') Tri-(p-cyclohexyl phenyl) phosphate.- 2 A (b) (b') 'Iri-go-xenyl) phosphate 2 A (b) (b') Tria-naphthyl) phosphate. 2 A (b) (b') 'Iri-(B-naphthyl) tphosphate. 2 A Tri-benzyl phosp atc 2 A (b) (b') Mono-phenyl di(p-tort.-butyl phenyl) phosphat 2 A (b) (b') Dipbcnyl mono-(p-tert.-butyl phcnyl) phosphat 2 A (b) (b') Diphenyl mono-(o-xcnyl) phosphate. 2 A (b) (b') Mono-phenyl li-(o-xenyl) phosphate. 2 A (b) (b') M0no-(p-tcr.hutylphenyi) diguaicyi 2 A (b) (b') n-Orcsyl phenylo-xenyl phosphate 2 A (b) (b') M'ono-cthyl diphenyl phosphate 2 A (b) (c) Halogen-bearing compounds:

Tri-(B-chlorethyl) phosphate. 2 A (b) (a') A Tri-o-(dichlor cresyl) phosphot 2 A (b) (b') A 'lri-(o-chlorphenyl) phosphate. 2 A (b) (b') B (1") 'lri-(p-chlorphenyi) phosphatc... 2 A (b) (b') B (1") 'Iri-(chlor cresyl) phosphate 2 A (b) (b') B 'iri-(o-chlor hcnzyi) phosphatc.. 2 A (b) (b') B (1) Di-(o-chlorphenyl)mono-(0-cresyi) phosphate. 2 A (b) (b') B (1) Mono(o-chlorphcnyl)di-(m'cresyi) phosphate. 2 A (b) (b') B"(l) Mono(o-chlorphenyl)di-(p-cresyl) phosphate... 2 A (b) (b') B (l Mono-(o-chlorphenyl)diphcnyl phosphate.... 2 A (b) (b') B (1") Di-(o-chlorphenyl)morlo-phcnyl phosphate. 2 A (b) (b' B(1") 'lri-(2-ch1or 4-tert.-b11tyl phenyl) phosph e. 2 A (b) (b') B (1") N[ono-(n-tert.-hutylphenyl)dichlorphanyl) phosphatc. 2 A (b) (b') B'(1") Mono-(nyclohexylphenyl)dio-chlorphcnyl) phosphate. 2 A (h) (b') B'(1". Mono-(B-nnphthyl)di-(o-chlnrphenyl) phosphate '2 A (l: (b') B (1") Mono-guaiacyi di-(o-chlorphcnyl) phosphate 2 (b) (5) B (1) Phenyl o-chIorphenylo-cyolohexylphcnyl phosphate 2 A (b') T! I) Mono-(o-chlorphenyl)di-(n-bntyl) phosphate 2 (h) (0) W (1) Mono-(fl-chlorethyl') di-phenyl phosphate v 2' A (b) (c) 'Iri-(chlorcyclohexyl) phosphate... 2 A (h) (h) i'(2) Tri-(chlor-tctrahydro (uriuryl) phosphate... 2 A (b) (b') B (3) Derivatives of carbonic acid 3 Esterscar honates.-. 3 A

(Di) ethyl carbonate 3 A (h) (a') (Di) amyl carhonate-. 3 A (b) (0') (Di) lauryi carbonate--- 3 A (b) (a) (Di) phenyl carbonate. 3 A (b) (0) (Di) cresyl carbonate 3 A (b) (b') (Di) (o-cresyDcarbonate 3 A (b) (b') (Di) hcnzyl carbonate 3 A (b) b') Mono-ethyl mono-phony] carbonate 3 A (b) (c) Halogen-bearing compounds:

Di (B-chlorcthyl) carbonate 3 A (b) (n) A Di (p-chlo'rphenyl) carbonate 3 A (b) (b') B (1") Di o-chlorphenyl) carbonate v3 A (b) (b') B (1) Di o-(a-dichlorctesfl) carbonate 3 A (b) (b') Derivatives of sulphurous acid 4 Estcrs-sulphites 4 A Ethyl sul hite..--'. 4 A-(b) (o') Bntyl (su phite) 4 A (b) (o') Lauryl snlphite 4 A (b) (0) Benzylsulphite 4 A (b) (b') Ohlorbem. lsnlphite 4 A (I2) (11) B (1) Snlpbinic an (is 4 B Benzene sulphinic acid. 4 B

p-Ethyl benzene sulphinic acid 4 B Derivatives of lphosphorous acid 5 Tri-ethy phosphitc 5 A h) (n') Triphcnyl phosphite; w. 5 A (b) (b') 'lri-( blorphenyl) phosphiton 5 A (b) (b') B (1") Derivatives of nitric acid 6 Esters-nitrates 6 A (0) Amy] nitrate--- 6 A (b) (o) Lauryl nitrate.- 6 A Benzyl nitrate.- "6 A-(b) (b') Chlorbenzyl nitrate 6 A (b) (b') B (1) Nitro-compoun 2-- 6 B Nitroropane-. 6 B

Nitrocxane.... 6 B

Nitro-lauryl alcohol 6 B Nitro-ctbylbenzone. 6 B

Nltm-chiorhenzcnc. 6 B B (1") Nitro-diphenyl-.- 6 B Nitro-phenol- 6 B Nitro-chlorphonol. 6 B B (1") Derivatives of nitrous acid. 7

Estersnitritcs.... 7 A

Amyl nitrite... 7 A b) (d) Lauryl m trita.- 7 A b) d) Bcnzyi nitrite... 7 A b) b) Ghlorbcnzyl nitrite -l 7 A b) b) B(l) Classification I II III Derivatives of nitrous acid-Continued.

Nitroso-compounds:

Nitrnsnhnnmnn Nitroso Nitrosochlorbenzene WWW Derivatives of oxyhalogen acids Esters:

Arnyl hypochlorite.

Amy] chlorite Amy] chlorate Amyl perchlorate Derivatives of cyamc acid Esters-cyanates and isocyanates Ethyl cyanate Amy] cyanate... Lauryl cyanatd. llauryl isocyanats.

Benzyl cyanate llenzyl isocyanate Ghlorbenzyl cyanate In the foregoing specification, as well as in the claims, certain compounds and groups of compounds have been defined as halogen-bearing or halogen-containing. f such compounds the chlorine-bearing species are preferred, particularly due to the lower cost and greater availability of chlorine as compared to the other halogens. Certain of the other halogens such as fluorine and bromine, for example, do act slightly differently from chlorine, but it has been found that any advantage in the use of other halogens over chlorine is generally not compensated for'by the increased cost.

For most uses it is usually preferable to employ only the most stable compounds; that is,

those which are most resistant to thermal decomposition and/or hydrolysis, because of the corrosive effect of the resulting decomposition products. Of the halogen-bearing compounds, these requirements are best met by those compounds in which the halogen is attached to a carbon atom which is part of a ring structure, and preferably part of a benzenoid ring structure.

However, where extremely severe pressure conditions are to be overcome, for example, in certain metal working operations such as extruding, drawing, etc., the effectiveness of the compound as a means of preventing scoring of the metal surfaces, such as the die and metal being worked, is of much greater importance than the corrosive effect. In these cases it may be advisable to use a compound which may be too unstable, or of too corrosive a nature, for ordinary applications.

It is noteworthy that, since phosphoric acid has a certain corrosion-inhibiting effect, the use of organic derivatives of phosphoric acid of the less stable types does not necessarily result in harmful corrosive effects. This fact makes this class of compounds particularly useful.

The exact mechanism by which addition agents, contemplated for use by the present invention, are effective in increasing the film strength of lubricants is not clearly understood, but it has been suggested that certain elements, or groups of elements, may react with the metal atoms of the bearing surfaces, due to the stress of the rubbing action under severe conditions. The metal-bearing compounds so produced may then act to prevent actual contact of the metal surfaces, and may thus exert an anti-fluxing action capable of inhibiting the welding together of a part-of one surface with a part of the other. It is assumed that scoring usually results from the tearing apart of such welded portions of the two surfaces.

The compounds contemplated by'this invention as addition agents contain acid radicles, or acid-forming groups and are, therefore, capable of reacting with metals to form such anti-fluxing materials under the conditions assumed by the theory above described. 4

Certain addition agents seem to be capable of improving the lubricating qualities of a lubricant in another way, that is by increasing the oiliness of the lubricant, or its ability to reduce friction. These materials appear to have in common the tendency to be strongly adsorbed by metal surfaces. Such a tendency is characteristic of oxygen-bearing compounds in general, andparticularly those which are of an acid, or acid-forming character. It would, therefore, appear that the addition agents of this invention are particularly well adapted for this purpose.

The halogen-bearing compounds of the type contemplated are particularly effective because of the presence of two separate means which may act to produce anti-fluxing materials, viz: the halogen, and the acid group. In addition, the presence of oxygen in the acid group, because of its tendency to be strongly adsorbed on metal surfaces, increases the effective concentration of the active ingredients at the bearing surfaces where they may function as required.

Range of compositions As previously indicated, this invention contemplates the use as a. lubricating composition of the so-called addition agents either singly or in combination with other addition agents and/or a suitable oil base. When used alone, the halogen-bearing compounds are usually preferred of which the following are notable examples:

Tri-(chlorcresyl) phosphate Tri-(o-chlorphenyl) phosphate Di-(o-chlorphenyl) mono-(o-cresyl) phosphate Mono-(o-chlorphenyl) di-(p-cresyl) phosphate Mono-phenyl di-(o-chlorphenyl) phosphate Di-phenyl mono-(o-chlorphenyl) phosphate For ordinary types of lubrication such as in the crankcase of internal combustion engines, it has been found that the two considerations which determine the amount of the addition agents which is to be added to a lubricating oil are, first, the cost of the resultant composition, and, second, the reduction of viscosity of the lubricat ing composition as a result of the presence of the addition agents.

- sitions in accordance with the present invention are particularly useful when added to gasoline and like motor fuels for the purpose of affording lubrication to valves and like parts not normally fully lubricated by the oil in the crankcase of the engine and are also effective to keep down and reduce carbon deposits in the combustion chamber. When the lubricating composition is employed for this last-named purpose, i. e., when added to a gasoline or similar motor fuel, the

percentage of addition agents present therein.

may be considerably higher than when the composition is used in the crankcase. A lubricating composition in accordance with the present invention and designed to be added to a fuel may contain up to 100% of the so-called addition agents, and certain of such addition agents, notably those which are halogen hearing may be used in their pure state.

Uses and advantages In addition to the advantages attained by the use of certain products contemplated by this invention to increase the film strength of lubricating oils or as lubricants possessing high film strength, other advantages may be obtained as follows. The compounds are in general relatively stable and therefore resistant to the composition oxidizing and to gum forming and sludge forming reactions, especially when used as crankcase lubricant in internal combustion engines. Certain of the compounds named are effective when present in mineral lubricating oil compositions to reduce the rate of change of viscosity with the temperature and usually have a tend.- ency to prevent precipitation of crystalline or gelatinous materials, such as waxes,.on chilling. Lubricants resulting from the use, either pure or mixed with other lubricating oils, of such products, therefore have the advantage of improving viscosity index and lowering pour point.

As previously indicated, the lubricating compositions made in accordance with the present invention are particularly applicable for use generally under high temperature and extreme pressure conditions which makes them particularly suitable for use as lubricants added to a fuel which passes directly into the combustion chamber.

It has been found that certain of the compounds above described either aloneor in combination with other materials such as lubricating oils are capable of reducing the rate of wear of the bearing surfaces, particularly during thin film lubrication, and. especially when one 01 the bearing surfaces is of a so-called bearing metal type such as babbitt, brass and bronze.

Other modes of applying the principle of our invention may be employed instead of the one explained, change being made as regards the composition and method herein disclosed, provided the ingredients or steps stated by any of the following claims or the equivalent of such stated ingredients or steps be employed.

We therefore particularly point out and distinctly claim as our invention:

' 1. A lubricating composition comprising the combination of a major proportion of mineral lubricating oil and a small amount of a tri-alkyl ester of phosphoric acid.

2. A lubricating composition comprising the combination of a major proportion of mineral lubricating oil and a small amountof tri-butyl phosphate.

3. A lubricating composition comprising the combination of a major proportion of mineral lubricating oil and a small amount of tril-ethyl phosphate.

4. A lubricating composition comprising the combination of a major proportion of mineral lubricating oil and a small amount of tri-lauryl phosphate.

AMOS T. KNU'TSON. ELDON F. GRAVES. 

